Controlling means for electric heaters.



RH. RICHARDSON, FJBOOTH & W. MEREDITH. OONTROLLING MEANS FOR ELEOTRIO HEATERS.

APPLICATION FILED APR. 16, 1908.

928,402. Patented July'20, 1909.

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B. H. RIGHARDSON, Pi BOOTH 61 W. MEREDITH. CONTROLLING MEANS FOR ELECTRIC HEATERS.

APPLICATION PILBI) APR. 16, 1908. 92b,402. A Patented July 20, 1909.

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EARL H. RICHARDSON, 01*

ONTARIO, FRANKLIN BOOTH, OF ALHAMBRA, AND WYNN MERE- DITH, OF SAN FRANCISCO, CALIFORNIA, ASSIGNORS TO PACIFIC ELECTRIC HEATING COMPANY, OF ONTARIO, CALIF ORN IA, A CORPORATION OF CALIFORNIA.

CONTROLLING MEANS FOR ELECTRIC HEATERS.

Specification of Letters Patent.

Patented July 20, 1909.

Application filed April 16, 1908. Serial No. 427,549.

To all whom it may concern:

Be it known that we, EARL H. RICHARD- sox, of Ontario, San liernardino county, California, FRANKLIN Room, of Alhambra, Los Angeles county, California, and VVYNN hli-iuunrrn, of San Francisco, San Francisco county, .alit'ornia, all citizens of the United States, have invented a new and useful Con trolling Means for Electric Ileaters, of which the following is a specification.

This in ventionrelatcs to controlling means for electric heaters and while applicable to electric heaters in general, is of especial advantage in electric laundry irons, and the main object of the lllYtllllOll is to automatict allv move the connection plug out of contact with the terminals, when the heat. reaches a certaiu' degree, to prevent excessive heating of the iron and resultant damage.

Another objcct is to accomplish this without int ertcring with the manual operation of the connection plug, leaving the same free to be manually withdrawn from the iron when desired.

-Other objects are to provide a construction which is simple, economical of manufacture, and accurate and sure in operation.

Another object is toenable the connection plug to be moved back into contact with the terminals after the heater has reduced in temperature sutticiently, and to enable the thermostatic device to be easily reset from the outside of the heater.

In the drawings we have shown the inven tion as applied to an electric laundry iron, and have shown two embodiments thereof.

teferring to the drawings; Figure 1 is a vertical longitudinal section through the laundry iron with the handle in elevation, with the connection plug in contact with the terminals and the thermostatic device set ready for operation, dotted lines showing the osition of the connection plug after it has een moved. out of contact with the terminals by the thermostatic device. Fig. 2 is a plan view of the body of the iron with the cover, and parts carried by the cover, removed. Fig. 3 is a transverse vertical section through the connection plug. Fig. 4 is a detail view, in plan, of the slotted disk. Fig. 5 is a plan view, in detail, of the spring. Fig. (3 is a vertical, longitudinal section through the iron showing another form of thermostat and dog. Fig. 7 is a plan view of the form shown in Fig. 4 of the body of the iron, with the cover and parts carried thereby removed. Fig. 8 is an enlarged horizontal longitudinal section through the telescopic thermostat of Fig. 4, showing the normal position of the parts before expansion by heat. Fig. 9 is a view similar to Fig. 6, showing the position of the parts after expansion by heat. Fig. 10 is an enlarged transverse section on line a; "-w Fig. 5.

Referring to the form shown in Fig. 1, -1 designates the body of the iron which is holloi Y and contains electrical heating means which consists of two cores 2 wound with wire 3, the two heating units thus formed being angularly disposed with respect to each other, thus leaving a triangular recess between them within the body of the iron. 'lwo posts 41 are secured to the rear portion of the body and each post is connected with the wire 3 of one of the heating units. Washers 5 insulate the posts 4 from the body 1. The rear end of each post 41 carries a terminal blade 6, and the terminal blades 6 are parallel with each other and extend upwardly. A cavity 7 is formed in the body of the iron near the heel and is closed at the top by a disk 8, the disk 8 being retained in position by slightly upsetting the wall of the cavity over the rim of the disk. The disk 8 is provided, as shown in Fig.4, with a slot S) and two notches 10, and the lower end of a dog 11 projects through the slot 9. A pin 12, in the lower end of the dog, projects from both sides thereof and prevents the dog from upward displacement when in the rear end ofslot 9, while the dog may readily be inserted or removed, when desired, by moving it slightly forward so that the notches 1O permit passage of the ends of pin 12. The dog thus being easily detachable has a loose or pivotal connection with the body of the iron which permits the dog to swing. The dog is also formed with a lower shoulder 13 and an upper shoulder 14. A thermostat comprising a rod 15 is arranged between the heating units 3. The rod 15 is preferably formed of brass or copper and its front end rounded and supported in a shallow cavity 16 formed in the body of the iron, while the rear end of the rod 15 is forked to rethe rear end of the rod 15 when the dog 11 is tilted forward and in the position shown in full'lines in Fig. 1. While it mightappear from Fig.2 that the forward end of the rod-15 was in contact with the heating -units, it should be understood that each heating unit is triangular in cross section,

as indicated in Fig. 1, so that there is sufli nection plug 22, and the front wall of thesocket 21 has avertical slot 23 through which projects the rear end of a flat spring 24, the latter being secured by bolts 25 to the bail 26 'whichis attached to the cover 17 and supports the handle 27 The spring 24 has a slot 28, as shown in Fig. 5, through which the upper end of the dog 11 projects, and spring 24 is normally held sprung down and retained under tension by the dog 11, as

shown in Fig. l, and the rear endof the spring 24 lies directly under the connection plug 22. The connection plug 22 has two -U-shaped spring clips 29, as shown in Fig. 3, which respectively grip the terminal blades 6, when the plug is in its lower position, and thusclose the circuit through the heating units. The respective clips 29 are connected with wires 30. v

When the iron becomes heated to a certain degree, above which it is not advisable to'let the heat rise, the rod 15 has expanded sufliciently to swing back the dog 11 and disengage the spring 24, whereupon the lattersprings up into position shown in dotted lines Fig. 1, and shifts the connectionplug 22 up with it to the position shown in dotted lines, sothat the clips 29 are moved out of connection with the terminal blades '6 and the circuit is broken. It will. be noted that the connection plug is still retained in the receptacle 21. To again close the circuit it is simply necessary to push down the connection plug by hand, which will depressthe spring, whereupon the dog 11 may be again hooked forward'to engage the spring, but it will be' observed that the dog will not engage the spring again until the iron has cooled somewhat to allow .the

rod 15 to contract and permit of the necessary movement of the" dog 11 to cause it to engage the spring. The connection plug 22 may readily be withdrawn from the receptacle'at any time without interfering with the automatic device, and as the con nection plug is perfectly accessible and as the upper end of the dog 11 is easily manipulated, there are no parts to unscrew or detach in resetting the device.-

In the form shown in Figs. 6 to 10 inclusive the construction is very similar, the only difference being in the method of pivoting "the dog and in the construction of the thermostat. In this form the dog is ivoted to a stud 40 screwed to the body of the iron, while the thermostat comprises a plurality of telescopic tubes consisting of an outer "tube 41, which is split longitudinally, in

the front end of which fits the bell shaped shank 42 of a flat head 43', the shank and head being made of a single piece of metal formed to shape. A few layers of mica 44 are wound around the flat head 43 and tied by wire 45. The flat head 43 being thin, rests on the bottom of the hollow body 1 and lies between the forward ends of the two heating units 3, thus permitting the thermostat to lie in a horizontal position which gives room for the increased diameter of the thermostat necessitated by the plurality of tubes. Slidable within the outer tube 41 is a tube 46 formed of a material having a less co-eflicient of expansion, such, for example, asiron, and the tube 46 is also split longitudinally and at its forward end. has an inturned flange 47, and at its rear end has an outturned flange 48 which abuts against the rear end of tube 41. Slidable within the tube 46 is a split copper tube 49, the for-' ward end of which abuts the flange 47 of tube 46, and slidable within the tube 49 is an iron tube 50 split longitudinally and having an inturned flange 51 at its forward end and an outturned flange 52 at its rear end, the flange. 52 abutting the rear end of the tube 49.- \Vithin the tube 50 is a copper rod 53 the front end of which abuts the inturned v flange 51 of tube 50, and the rear end of rod 53 has a fork 54 which straddles the dog 53 and rests upon the top of stud 40. When the parts are not heated, the several telescopic tubes-and the rod 53 are contracted in length, as shown in Fig. 8, and the dog 55 is in engagement with spring 24, thus holding the latter under tension. Under the influence of heat the copper tubes 41, 49 and rod 53 expand at a greater rate than the iron tubes 46 and 50, which results in elongating the thermostat, and as the front'end of the thermostat is .prevented from forward movement by the flat head 43 abutting against the body of the iron, the rod 53 is caused to project rearwardly a distance equal to the combined expansion of the tubes 41 and 49 and rod 53 less the slight amountof expansion of" tubes 46 and 50. Thus the desired amount of backward movement of rod 53 is accomplished with a thermostat of the minimum length by the multiplication of the expansibility of the several tubes. This gives a considerable range of-movement which is sufficient to throw the dog out of engagement with the spring when the heat reaches the maximum desired degree.

\Vhat we claim is 1. In an electric heater, for, a socket adjacent the terminals, a detachable connection plug slidable in the socket into or out of connection with the terminals, and a thermostatic device for sliding the plug a limited distance in the socket to move it out of connection with the terminals but not out of the socket.

2. In an electric heater, terminals therefor, a connection plug for said terminals, a thermostat, means independent of the plug and controlled by the thermostat for snapping the plug out of connection with the terminals, and means independent of the plug for supporting the plug when it is out of connection with said terminals.

3. In an electric heater, terminals therefor, a connection plug for said terminals, a spring for operating the plu and independent thereof, means for holcing the spring under tension, and a thermostat. or actuat' ing said means to allow the spring to move the plug out of connection with said terminals.

4. In an electric heater, terminals on the heater, a socket on the heater into which said terminals project, a connection plug for the terminals slidable in the socket, a thermostat, and means controlled by the thermostat for moving the plug out of connection with the,

terminals.

5. In an electric heater. terminals therefor, a socket on the heater. :1 connection plug for the terminals slidable in the socket, a spring projecting into the socket under the plug, means for holding the spring under tension, and .a thermostat for operating said means to release the spring.

6. In anelectric heater, a body portion, electric heating means therein, terminals on the body connected with the heating means, a cover on the body portion, a socket on the cover. a connection plug slidable in the socket, a thermostat, and means controlled by the thermostat for moving the plug out of connection with the terminals.

7. In an electric heater, a body portion, electric heating means therein, .terminals on the body connected with the heating means, a cover on the body portion, a socket on the cover, a connection plug slidable in the socket, a thermostat. a spring on the cover extending into the socket into operative relation with the plug, and means controlled by the thermostat for dctachably holding the spring under tension.

terminals there 8. In an electric heater, a body portion having a cavity, a pair of rearwardly diverging electric heating units in said cav1ty,'a

. thermostat in said cavity between the units, terminals connected with the units, a connection plug on the terminals, and means controlled by the thermostat for moving the plug out. of connection with the terminals.

9. In an electric heater, terminals therefor, a connection plug on the terminals, a spring on the heater for moving the plug, a dog in the heater engaging the spring to hold it under tension, and a thermostat in the heater comprising a rod with a notched end engaging the dog for actuating said do 10. In an electric heater, terminals therefor, a connection plug on the terminals, a spring on the heater for moving the plug, a dog in the heater engaging the springto hold it under tension, and a thermostat in the heater for actuating said dog, said dog being detachably articulated in the heater.

11. In an electric heater, terminals therefor, a connection plug on the terminals, a spring on the heater for moving the plug, said spring having a slot, a dog in the heater engaging in the slot in the spring to hold it under tension, and a thermostat in the heater for actuating said dog.

12. In an electric heater, terminals therefor, a connection plug for the terminals, means for moving the plug off the terminals, a dog restraining said means, and a removable thermostat abutting at one end against the do and at its other end against a fixed part oi the heater.

13. In an electric heater, for, a connection plug for the terminals, a bail on the heater, a spring attached to the bail and projecting to the plug for moving the plug, a thermostat in the heater, and means operated by the thermostat for con trolling the spring. I

14.- An electric heater, terminals therefor, a detachable connection plug for said terminals, and temperature controlled means independent of said plug for moving said plug to break the circuit.

EARL H. RICHARDSON. FRANKLIN BOOTH. \VYNN MEREDITH. \Vitnesses for Richardson:

HARRY BECK, C. V. SMITH. iVitnesses for Booth:

Gnome T. Hackney, FRANK L. A. GRAHAM. Witnesses for Meredith: ILV. Csozma,

P... Cor-a.

terminals there- 

